I seldom see pro-2A gun owners becoming anti-gun. But I often see previously anti-2A gun owners becoming pro-gun after gun purchase.
You would think that they learned a lesson...
Selective information processing is a hindrance to understanding the right for the RKBA.
There are quite a few folks in the gun world who have come out strongly against the ownership of military style semiautomatic firearms (to use the term of the month). Need I post a list of supposedly progun politicians who have spoken in favor of such from the 'conservative' wing: Bush, Romney, Trump, Dole, Bjork, etc. Gun world folks such as Zumbo, the guy from Guns and Ammo, etc. Now some of them recant when faced with political consequences or financial consequences but that is just being craven and not a real change of world view.
Now - learning a lesson. The NZ population does not see the ownership of personal firearms as a deterrent to foreign invasion. They face nothing like the UK did in WWII. Tell them that they need a bunch of civilians with rifles to stop the Chinese? They will laugh at you.
Even if you told the American population that we need rifles for defense against invasion, they will laugh at you. I recall whacky posts that the Chinese were loaded up in ships in Long Beach harbor, the UN troops were going to invade to take our guns, the Chinese were massing on the Mexican border. Just looked nuts. The Yamamoto quote is bogus. The Swiss had a militia army but had their bacon saved more by collaboration with the Nazis and the threats to blow up the tunnels through the Alps, that they let the Nazis used.
Cliches and inappropriate analogies will not win the debate in the USA. NZ won't become a crime ridden hell hole or some kind of tyranny. Find better arguments for the RKBA in the USA.